Add skipFormatContainerFallbackCheck to keep persisted Content Model path valid

[JiuqingSong]

Summary

When formatInsertPointWithContentModel persists the Content Model group path during DOM-to-Model conversion (so the formatting callback can later reference it), a FormatContainer that gets created for a container element (e.g. a <div> with margin/padding) can later fall back to a plain paragraph when it only wraps a single paragraph. That fallback removes the FormatContainer from the model, leaving the persisted path pointing at a node that no longer exists — an invalid path.

This adds a skipFormatContainerFallbackCheck option that keeps the FormatContainer in that scenario, so the persisted path stays valid and the formatting callback works correctly.

Original bug: https://outlookweb.visualstudio.com/Outlook%20Web/_workitems/edit/426559

Changes

• formatContainerProcessor: skip the paragraph-fallback when context.skipFormatContainerFallbackCheck is set.
• DomToModelOption / DomToModelSettings: add the new skipFormatContainerFallbackCheck flag.
• createContentModel: propagate the option onto the DOM-to-Model context (set only when truthy, matching the existing if (selection) pattern so the context isn't polluted with an undefined key).
• formatInsertPointWithContentModel: pass skipFormatContainerFallbackCheck: true, with a comment explaining why.

Tests

• New formatContainerProcessor tests for the skip behavior (div / div-with-id kept as FormatContainer; blockquote unaffected).
• createContentModel wiring tests (option propagated when set, absent otherwise).
• Updated formatInsertPointWithContentModel assertions to expect the new option.

All affected tests pass via yarn test:fast, and yarn eslint is clean.

🤖 Generated with Claude Code

[github-actions]

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[Copilot]

Pull request overview

This PR adds a DOM-to-Content-Model conversion option to preserve FormatContainer nodes when formatInsertPointWithContentModel needs a stable persisted group path during formatting.

Changes:

• Adds skipFormatContainerFallbackCheck to create-model options/settings.
• Propagates the option through createContentModel and applies it in formatContainerProcessor.
• Enables the option for formatInsertPointWithContentModel and updates/adds related tests.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/roosterjs-content-model-types/lib/context/DomToModelSettings.ts	Adds runtime setting for skipping format-container fallback.
packages/roosterjs-content-model-types/lib/context/DomToModelOption.ts	Exposes the new create-model option.
packages/roosterjs-content-model-dom/lib/domToModel/processors/formatContainerProcessor.ts	Preserves FormatContainer when the new context flag is set.
packages/roosterjs-content-model-dom/lib/domToModel/context/createDomToModelContext.ts	Adds explicit return type to context factory helper.
packages/roosterjs-content-model-dom/test/domToModel/processors/formatContainerProcessorTest.ts	Covers skip-fallback behavior for div containers and blockquote.
packages/roosterjs-content-model-core/lib/coreApi/createContentModel/createContentModel.ts	Propagates the option onto the DOM-to-model context.
packages/roosterjs-content-model-core/test/coreApi/createContentModel/createContentModelTest.ts	Tests option propagation and absence when unset.
packages/roosterjs-content-model-api/lib/publicApi/utils/formatInsertPointWithContentModel.ts	Enables the option for insert-point formatting to keep persisted paths valid.
packages/roosterjs-content-model-api/test/publicApi/utils/formatInsertPointWithContentModelTest.ts	Updates assertions for the new DOM-to-model override option.

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